The clinical spectrum of mitochondrial diseases has expanded dramatically i
n the last decade. Abnormalities of mitochondrial function are now thought
to participate in a number of common adult diseases, ranging from exercise
intolerance to aging. This review outlines the common presentations of mito
chondrial disease in ICUs and in the outpatient setting and discusses curre
nt diagnostic and therapeutic options as they pertain to the pulmonary and
critical-care physician.